North Downs line electrification

[Deepgreen]

Here we go again. The regulations do not apply. A new third rail up slow came into use into Eastleigh last year. No prosecutions that we have heard of.
The I squared V losses are counteracted by far lower capital costs & the other pro DC factors I & others posted earlier. Third rail,or rather costly battery packs, are the only option for north downs. Network Rail's sickening performance have ruled out new AC,unless essential. But others may do it more cheaply if Grayling's plans are not just puff.

I suspect another short stretch will be introduced soon when the Redhill re-modelling takes effect. The up side, London end long siding has just been re-laid and I believe it is to be electrified as far as the crossover to the up main as part of the platform zero works. This will allow those concrete-carrying passenger trains to use it!

However, these examples do not increase route mileage, only track mileage, which may be where the distinction lies.

 

[QueensCurve]

So people deserve to die due to ignorance, do they?

Cue John Hurt and an iceberg

 

[najaB]

The I squared V losses are counteracted by far lower capital costs....

Capital costs are a one-off and can be paid for by borrowing which is paid off by lower operating costs.

 

[QueensCurve]

Here we go again. The regulations do not apply. A new third rail up slow came into use into Eastleigh last year. No prosecutions that we have heard of.
The I squared V losses are counteracted by far lower capital costs & the other pro DC factors I & others posted earlier. Third rail,or rather costly battery packs, are the only option for north downs. Network Rail's sickening performance have ruled out new AC,unless essential. But others may do it more cheaply if Grayling's plans are not just puff.

There is a difference between a very short extension and as major new electrification

The lack of prosecutions may reflect competent engineers desciding to comply with the regulation.

 

[HSTEd]

Here we go again. 3rd rail doesn't comply with the electricity at wporl regu;work regulations and losses in transmission are proprtional to the square of the curren. Hence it is grossly ineffiicent eeeven though the Southern has coped with it for a Century.

Electricity at Work Regulations - Regulation 7, Paragraph 116:

Electric railway and tramway operators, in conjunction with the Office of Rail and Road, have developed standards and safety specifications for the construction of those parts of their systems which use bare conductors at overhead and at track level, together with safe systems of work.

So it states that safe systems for third rail do exist and therefore implies that they should not be forbidden. I can't find anything in the text that says that third rail is forbidden, even the conductor insulation stuff goes on about As Far As Is Reasonably Practicable.

Which would probably mean continuous kickboards but beyond that I doubt anything else.

Capital costs are a one-off and can be paid for by borrowing which is paid off by lower operating costs.

At 6-8p/vehicle-km in extra losses it is going to take an awful long time to pay for the extra capital cost on a low traffic density route. And there are other costs associated with 25kV systems.

 

[Deepgreen]

Idle thinking the other day led me to the concept of the coating of conductor rails with robust plastic film when they are produced, to insulate all but the contact surface. I wonder if it would be cheap enough to be viable as it would not only protect against electrocution, but also against shorting through line-side debris.

I suspect that the plastic (recycled?) technology is cheap enough these days but that the replacement rate would not lead to a rapid enough coverage rate to justify the change before AC is adopted.

 

[HSTEd]

rapid enough coverage rate to justify the change before AC is adopted.

Don't make me laugh, its not good for me.

DC to AC conversion is dead, dead like the Electric Spine

 

[najaB]

At 6-8p/vehicle-km in extra losses it is going to take an awful long time to pay for the extra capital cost on a low traffic density route. And there are other costs associated with 25kV systems.

If the traffic density is that low, why bother electrifying in the first place (with either system)?

 

[HSTEd]

If the traffic density is that low, why bother electrifying in the first place (with either system)?

Because it is low traffic density only compared to high traffic density routes like the environs of Clapham Junction.

And the (comparatively) low up front costs of 3rd rail reduce the traffic density required to electrify. And whilst 3rd rail electric has a higher energy cost than 25kV electric - both still easily beat diesel on a marginal cost basis.

 

[najaB]

And the (comparatively) low up front costs of 3rd rail reduce the traffic density required to electrify.

It's lower cost than 25kV, but it's still expensive. It still takes a long time for DC to pay its way at low traffic density.

 

[HSTEd]

It's lower cost than 25kV, but it's still expensive. It still takes a long time for DC to pay its way at low traffic density.

In the absence of third rail capable bi-modes (for the moment) there is also a substantial network effect at play here in that long stretches of the line are already electrified. And the North Downs line is hardly the Far North Line in traffic terms.

 

[Deepgreen]

Don't make me laugh, its not good for me.

DC to AC conversion is dead, dead like the Electric Spine

You could well be right, but that's still not the official stance.

 

[JamesRowden]

It's lower cost than 25kV, but it's still expensive. It still takes a long time for DC to pay its way at low traffic density.

The franchise extension set the off-peak service level at 3tph once the extra stock is available and the new platform at Redhill is completed.

 

[najaB]

In the absence of third rail capable bi-modes (for the moment)...

A third rail capable bi-mode would actually be simpler than a 25kV AC one - no need for a transformer or high voltage electronics. I suggest that it is more likely than large extensions of the third rail network such as the North Downs line.

 

[JamesRowden]

A third rail capable bi-mode would actually be simpler than a 25kV AC one - no need for a transformer or high voltage electronics. I suggest that it is more likely than large extensions of the third rail network such as the North Downs line.

Electrification of the North Downs would be two short infills of the third rail network.

 

[najaB]

Electrification of the North Downs would be two short infills of the third rail network.

I believe it was quoted as around 30 miles earlier in the thread. It's hard to justify that as 'short'.

 

[HSTEd]

A third rail capable bi-mode would actually be simpler than a 25kV AC one - no need for a transformer or high voltage electronics. I suggest that it is more likely than large extensions of the third rail network such as the North Downs line.

Well yes, but third rail pure electric units are also cheaper than 25kV electric ones for the same reason.

But having bi-modes for want of 30 mile electrification seems rather excessive, especially if it is the first such project to be considered.

Now the WEML on the other hand is screaming out either for cut price electrification or third rail bi-modes. I would prefer the former but I doubt either will actually occur. The fiction of DC-AC conversion will prevent any real improvements to the lot of the DC country railway by stifling all other investment.

It would be nice to see an estimate for third rail electrification costs that hasn't been blatantly cooked by Network Rail to make 25kV look good.

 

[JamesRowden]

I believe it was quoted as around 30 miles earlier in the thread. It's hard to justify that as 'short'.

That is the total length of the two non-electrified sections. In the middle there is Ash to Shalford junction which passes through Guildford Station and shares a tunnel with the mainline between London and Portsmouth. Locations where AC and DC electrified networks interface apparently create complications. Also having lines dual electrified also causes complications and there is a limit to the distance of track which can be dual electrified. So is the cost of having at least 4 new locations where trains need to be capable of transferring between AC and DC power worth it (assuming that the electrification around Guildford is not all converted to AC)?

 

[HSTEd]

That is the total length of the two non-electrified sections. In the middle there is Ash to Shalford junction which passes through Guildford Station and shares a tunnel with the mainline between London and Portsmouth. Locations where AC and DC electrified networks interface apparently create complications. Also having lines dual electrified also causes complications and there is a limit to the distance of track which can be dual electrified. So is the cost of having at least 4 new locations where trains need to be capable of transferring between AC and DC power worth it (assuming that the electrification around Guildford is not all converted to AC)?

But all that electrification is going to be DC for the forseable future.

 

[Phil.]

There is a difference between a very short extension and as major new electrification

The lack of prosecutions may reflect competent engineers desciding to comply with the regulation.

In railway terms the North Downs is a simple fill-in. A few miles from Reigate to Shalford Junction then Ash to Wokingham. About 25 miles in all.

 

[najaB]

Well yes, but third rail pure electric units are also cheaper than 25kV electric ones for the same reason.

However, they tend not to go very far once the juice rail runs out.

 

[Deepgreen]

In railway terms the North Downs is a simple fill-in. A few miles from Reigate to Shalford Junction then Ash to Wokingham. About 25 miles in all.

Not "a few miles" then. It won't happen, mainly because, unless the NDL becomes part of a wider spine network, there will not be the demand to justify the frequency of trains that would be needed to make a business case for the electrification and re-signalling (with platform lengthening and possible overtaking places) that would be required for a more frequent mix of semi-fast and stopping trains. The increase to 3tph next year is said to be pushing the limits of the signalling on the NDL (which I find hard to believe, but there it is). The junctions with main lines will also, according to the operators, preclude any paths for extensions to other destinations such as Brighton, Oxford and so on, so through working won't happen.

The 'status quo' will remain for decades, with other DMUs replacing the Turbos in due course, I suspect.

 

[greaterwest]

Not "a few miles" then. It won't happen, mainly because, unless the NDL becomes part of a wider spine network, there will not be the demand to justify the frequency of trains that would be needed to make a business case for the electrification and re-signalling (with platform lengthening and possible overtaking places) that would be required for a more frequent mix of semi-fast and stopping trains. The increase to 3tph next year is said to be pushing the limits of the signalling on the NDL (which I find hard to believe, but there it is). The junctions with main lines will also, according to the operators, preclude any paths for extensions to other destinations such as Brighton, Oxford and so on, so through working won't happen.

The 'status quo' will remain for decades, with other DMUs replacing the Turbos in due course, I suspect.

As has been mentioned already in this thread at some point I believe, the signalling between Wokingham and Ash Junction leaves a lot to be desired - from what I remember, a train cannot leave arrive at Farnborough North until the preceding train has cleared the signal at Wokingham.

 

[Deepgreen]

As has been mentioned already in this thread at some point I believe, the signalling between Wokingham and Ash Junction leaves a lot to be desired - from what I remember, a train cannot leave arrive at Farnborough North until the preceding train has cleared the signal at Wokingham.

Really?? That's about nine miles! Surely the section can't be that long?

 

[Ianno87]

Really?? That's about nine miles! Surely the section can't be that long?

It's not *quite* that bad. Train 2 cannot depart Blackwater (signal WM531) until Train 1 has arrived at Wokingham (clearing WM4)

 

[Deepgreen]

It's not *quite* that bad. Train 2 cannot depart Blackwater (signal WM531) until Train 1 has arrived at Wokingham (clearing WM4)

That's still over six miles! Why the huge distance here?

The other factor is of course that the Wokingham area signalling is the least reliable on the NDL, in my experience.

 

[greaterwest]

It's not *quite* that bad. Train 2 cannot depart Blackwater (signal WM531) until Train 1 has arrived at Wokingham (clearing WM4)

Yes, that was it. Thank you for clarifying.

Still as Deegreen said, it's quite bad.

 

[swt_passenger]

That's still over six miles! Why the huge distance here?

Is it still only two aspect signalling with long blocks? Same reason the Netley line from Fareham to Southampton has large headways - it is only about one step up from semaphore days...

 

[Phil.]

Not "a few miles" then. It won't happen, mainly because, unless the NDL becomes part of a wider spine network, there will not be the demand to justify the frequency of trains that would be needed to make a business case for the electrification and re-signalling (with platform lengthening and possible overtaking places) that would be required for a more frequent mix of semi-fast and stopping trains. The increase to 3tph next year is said to be pushing the limits of the signalling on the NDL (which I find hard to believe, but there it is). The junctions with main lines will also, according to the operators, preclude any paths for extensions to other destinations such as Brighton, Oxford and so on, so through working won't happen.

The 'status quo' will remain for decades, with other DMUs replacing the Turbos in due course, I suspect.

Compared with DC electrification schemes such as Bournemouth - Weymouth and Tonbridge - Hastings it's a piffling distance. Even the terrible signalling on the NDL can handle three trains per hour.

 

[Deepgreen]

Compared with DC electrification schemes such as Bournemouth - Weymouth and Tonbridge - Hastings it's a piffling distance. Even the terrible signalling on the NDL can handle three trains per hour.

Indeed, but those schemes were 'then' - the 'now' precludes significant new route mileage.

Yes, the signalling can handle 3 tph, which is what is to be provided next year, but I still can't get my head round a signalling block section of over six miles from Blackwater!! Is there, I wonder, any longer in the country with conventional signalling?